I just want to say this: if you can get a good fit, the DDM can offer a more open experience, but overall enjoyment is easier with he A1 because it is an easy earphone to use.
When I say perfect, remember that I judge certain aspects in certain ways. There is no such thing as fhll metric perfection. You will never get perfect fit with perfect sound with perfect build. And even if one of those areas is damn good, it may not match your preferences.
Overall, I feel that the A1 is a better buy than the ortofon because it is better to wear outside unless you want the extra few decibels of isolation. Again, with good fit, the A1 is very good. And can isolate with the best semi-open earphones.
The DDM is the antithesis of utility, but then it was designed by japanese audiophiles. Dmitri has helped me understand a little about them, but I know enough: they hardly ever think of anything but sound. They don't care if the earphone is weak or useless outside bedause audiophiles must be very lazy creatures. That explains cables like the older nylon coated FAD and the ortofon.
The A1 comes close to perfect ergonomics for outside, but it should have a stonger cable, something like what audio technic a use in the ck10